The most significant change: Jungle Disk Desktop Edition 3.0 adds Dropbox-style file-syncing to its existing back-up services: Drop a file into a synced folder, and it’ll be available from any of your other computers (including Windows and Linux machines). The company says the update also adds more efficient incremental backups, better revision tracking (so you can restore a file from a specific backup set), and improved Web access to your files.

At the same time, the company has released a new service, Simply Backup. As the name implies, it just does backups; it doesn’t do file-syncing.

For business users, the company’s Workgroup Edition, which lets multiple users use a single backup account, has also been updated to version 3.0; it gets the same improvements (file-syncing and so on) as the Desktop product. The company has also announced a new Server Edition, but it works only on Windows and Linux servers.

Asked what differentiates Jungle Disk from its many competitors, company officials say it’s the only online backup service that allows you to specify the cloud-storage provider—Rackspace Cloud Files, Amazon S3, or both—it uses to store your files. They also claim that their service offers truly unlimited storage space; there’s no limit on how much data you backup, either in total or per month, and no maximum file size.

The Jungle Disk Desktop Edition costs $US3 ($A3.30) a month plus storage fees; the first 5GB are free, and you pay $US0.15 ($A0.17) a gigabyte after that. Simply Backup runs $US2 ($A2.20) a month, plus the same storage fees. The Workgroup Edition costs $US4 ($A4.40) per user per month; you get 10GB free, then pay $US0.15 ($A0.17) per gigabyte. Upgrades for the Desktop and Workgroup services are free for current Jungle Disk customers.